The present invention relates generally to the field of flexible tubes and more particularly is directed to an improved combination flexible tube and expeller suitable to apply measured quantities of a semi-liquid or paste-like material.
It is well known to employ collapsible tubes to retain and dispense numerous types of paste-like or semiliquid products such as toothpaste, shaving cream, food products, etc. Metallic type collapsible tubes have long been employed for this purpose, whereby upon squeezing, small quantities of the stored material can be applied through a nozzle directly to the area of use, for example a tooth brush.
More recently, it has been attempted to utilize nonmetallic collapsible tubes for similar purposes. Such tubes have been fabricated from usual types of sheet plastic materials which can be easily heat sealed or otherwise treated to the desired configurations for containing and dispensing a paste-like material.
While the metallic type of tube can usually be rolled at the bottom as the product is dispensed from the nozzle to thereby maintain a relatively tightly packed storage space as less and less material is retained, the flexible or plastic type of container can not be so rolled inasmuch as such collapsible type tubes inherently tended to unroll. When part of the semi-liquid contents has been expelled, the remainder can not be forced to remain near the nozzle. Rather, the very flexible nature of the tube causes the device to relax and the material can spread throughout the tube. Accordingly, as more and more product was dispensed or used, the partially filled flexible tubes were then increasingly more awkward to handle and required greater effort in dispensing through the nozzle.